THIS is the “white hot” evidence gathered by police from high in the sky that is being used to smash secret cannabis factories in Birmingham.

Glowing brightly against the dark background, a detached home in the east of the city stands apart from its nearest neighbour.

But that isn’t snow covering the roof – the image from the police helicopter’s thermal imaging camera actually shows the heat given off by a cannabis factory.

Commercial-sized farms have sprung up in quiet residential streets with increasing regularity in recent years.

But the police helicopter is being used to pinpoint the heat given off by the super-strong lights needed to cultivate the plants.

And it is proving successful in weeding out the blight of drugs by leading officers right to the front door in a new operation codenamed No Deal.

Over the last decade, the region has seen an explosion in the number of cannabis farms set up in houses and commercial premises.

Drugs barons get people to pose as respectable families in order to rent out properties but then convert rooms into giant greenhouses as it easier to grow the drugs in the country than try and smuggle it in.

To avoid the massive electricity bills needed to pay for the heating, they often bypass the meter.

But police are making in-roads into the gangs. According to the latest figures, West Midlands Police’s Cannabis Disposal Team recovered more than £22 million worth of drugs since October 2010.

It has dismantled more than 500 factories and seized almost 110,000 plants and preventing their illegal crop from reaching the streets.

The team has even uncovered factories hidden in secret basements in a bid to hide the tell-tale heat signature.

Despite the criminals’ best efforts to hide it, heat had to escape the building somewhere and the officers on board the helicopter were on the look-out for unusual signs of where it might have been diverted.

In the last month, police have made major seizures, including:

n More than 200 plants were found growing in a posh two-bedroom apartment in Liberty Place, Ladywood, on February 14.

n A huge cannabis factory containing 2,500 plants worth £1 million was found at an industrial unit on Ash Street, Bilston, on January 30.

n Days before, more than 300 plants were found in the bedrooms and loft of a house in Ermington Crescent, Hodge Hill, after the force helicopter flew overhead and detected large amounts of heat coming from the house.

n Police discovered almost £500,000 of cannabis in a derelict factory, next to the Old Rep Theatre, in Station Street, Birmingham city centre on January 26.

n Following a tip-off, more than 400 plants were found hidden in the loft of a property in Ashcroft Road, Ladywood, at 10pm on January 22.